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Subject[PATCH 2/2] drivers: firmware: scmi: Extend SCMI transport layer by trace events
Date
From: Lukasz Luba <lukasz.luba@arm.com>

The SCMI transport layer communicates via mailboxes and shared memory with
firmware running on a microcontroller. It is platform specific how long it
takes to pass a SCMI message. The most sensitive requests are coming from
CPUFreq subsystem, which might be used by the scheduler.
Thus, there is a need to measure these delays and capture anomalies.
This change introduces trace events wrapped around transfer code.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
drivers/firmware/arm_scmi/driver.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 3eb0382491ce..0fda9b418bc6 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -29,6 +29,9 @@

#include "common.h"

+#define CREATE_TRACE_POINTS
+#include <trace/events/scmi.h>
+
#define MSG_ID_MASK GENMASK(7, 0)
#define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr))
#define MSG_TYPE_MASK GENMASK(9, 8)
@@ -439,6 +442,9 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
if (unlikely(!cinfo))
return -EINVAL;

+ trace_scmi_xfer_begin(xfer->hdr.id, xfer->hdr.protocol_id,
+ xfer->hdr.seq, xfer->hdr.poll_completion);
+
ret = mbox_send_message(cinfo->chan, xfer);
if (ret < 0) {
dev_dbg(dev, "mbox send fail %d\n", ret);
@@ -478,6 +484,9 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
*/
mbox_client_txdone(cinfo->chan, ret);

+ trace_scmi_xfer_end(xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq,
+ xfer->hdr.status);
+
return ret;
}

--
2.17.1
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